Biology

Butterfree resembles a vaguely anthropomorphic butterfly with a purple body. Unlike true insects, it only has two body segments and four light blue legs. The upper pair of legs resembles small, three-fingered hands, while the lower pair resembles long, digit-less feet. Butterfree has two black antennae, a light blue snout with two fangs underneath, and large, red compound eyes. Its two pairs of veined wings are white with black accents. The oval scales of a female Butterfree's lower wings are black, but white in males.

Butterfree's wings are covered with poisonous powders that fall off continuously as it flies. This powder repels water, enabling it to gather honey even in the rain. Butterfree will roam up to six miles from its nest in search of honey, which it carries with the hairs of its legs. It also consumes sap from trees pierced by Heracross, as seen in the anime. Butterfree is found in forests but has also been observed flying near the ocean as part of its migratory breeding pattern.

A pink Butterfree appeared in Bye-Bye Butterfree. Ash's Butterfree fell in love with it and fought to save it from Team Rocket. At the end of the episode, Ash released his Butterfree to mate with the pink Butterfree. The pink Butterfree reappeared in I Choose You!, which is set in a timeline different from the main series.

Other

Multiple wild Butterfree appeared in Bye-Bye Butterfree, where they engaged in a mating ceremony that Ash's Butterfree took a part of.

A Butterfree appeared in Spell of the Unown: Entei, under the ownership of Lisa. It was used in a battle against Ash and went up against his Bulbasaur; the match ended with Bulbasaur being dazed with Sleep Powder and finished off with a gust of wind.

Multiple Butterfree appeared in Butterfree and Me!, where they evolved from Metapod on Wayfarer Island. One Butterfree had been befriended by Ash as a Caterpie, and Ash spent much of the episode helping it eventually evolve into its final form.

Multiple wild Butterfree appeared in I Choose You!, where, much like the events of Bye-Bye Butterfree, they engaged in a mating ceremony that Ash's Butterfree took a part of.

Trivia

Butterfree was the first Pokémon shown in the anime to have an alternate color, pink. This has only been seen in a single female, and unlike a Shiny Butterfree, which has green eyes and pink wings, limbs, and snout, this Butterfree only differed in its pink body and wings.

Butterfree shares its category with Beautifly. They are both known as the Butterfly Pokémon.

Butterfree can be seen as a parallel to Beedrill. Both of their unevolved stages evolve at level 7 and again at level 10. They both go through metamorphosis-like evolution and have the same base stat total of 395. Also, while Beedrill is exclusive to Black and Black 2, Butterfree is exclusive to White and White 2.